Services Provided

Simulations of broadband random vibrations induced in spacecraft by external

acoustic pressures

Sine sweeps to identify resonances

Broadband random environments that do not simulate mission conditions

but are appropriate for precipitating impending failures due to

workmanship defects

Vibration of hazardous test articles, including pressurized

systems and explosive materials vibration in a thermal environment

Vibroacoustic structural testing to high sound

pressure levels of large structures,

components, and small subsystems

Modal characteristics

Natural frequencies

Damping ratios

Mode shapes

Mathematical or FEA

model correlation

Vibration Testing

Rocket boosters and spacecraft are subject to intense acoustic environments during launch, which

induce high levels of vibration in structural elements and equipment. In addition, elastic structural

interactions with propulsion systems and flight control systems can produce low-frequency,

high-deflection flight instabilities. Johnson Space Center (JSC) offers a wide range of tests needed

to evaluate all aspects of structural dynamics, including vibration, vibroacoustics, modal character-

istics, sound transmission loss, and shock testing. Ground testing to simulate launch-induced

vibration or to investigate structural dynamic characteristics has proven to be vital in developing

successful spacecraft programs. JSC facilities provide the capability to perform test and evaluation

of both aerospace and nonaerospace hardware.

National Aeronautics and Space Administration

www.nasa.gov

Vibration Testing

Vibroacoustic Testing

We have developed customer-friendly agreements to streamline business relationships and are eager to share

our unique facilities and expertise with new customers. We invite your inquiries regarding application or

adaptation of our capabilities to satisfy your special requirements. Briefings on general or specific subjects of

mutual interest can be arranged at JSC or at your business site.

Facility Testing Information http://jsceng.nasa.gov

Point of Contact Beth Fischer Associate Director JSC Engineering Directorate (281) 483-8991 beth.a.fischer@nasa.gov

Facility Frequency

Range Shaker Size Range Load Direction Displacement

General Vibration

Laboratory (GVL) 5 3000 Hz 4,000 40,000 lbf x, y, or z 1 to 2 peak-to-peak

Spacecraft Vibration

Laboratory (SVL) 5 2000 Hz

50 lbf shakers up to

8 x 10,000 lbf shakers x, y, or z 2 peak-to-peak

Hazardous Vibration

Test Stand 20 2000 Hz

11,000 lbf RMS

Up to 16,000 lbf sine

Up to 15,500 lbf random

x, y, or z 1 stroke

Hazardous Vibration

Test Stand

The Hazardous Vibration

Test Stand provides for

vibration of pressurized

systems and explosive

materials and vibration

within a thermal

environment. The test

stand supports test

articles (including fixture)

up to 2,000 lb. Vibration

capability includes sine,

random, and classical shock.

Modal Test and Analysis

Facility Facility Size Sound Pressure

Level

Spacecraft

Acoustic

Laboratory

Chamber size: ~39 x

47 x 75 high

Ceiling can be

lowered to ~33 high

High Ceiling

152 dB (current)

162 dB (future)

Low Ceiling

155 dB (current)

165 dB (future)

Sonic Fatigue

Laboratory

Chamber size: ~19 x

40 x 16

158 dB (current)

167 dB (future)

Input Excitation Flexible

Sine, random, burst random/chirp, sine on random (shaker driven)

Impact (impact hammer driven)

Operational (vibrating) test article

Shakers Wide Array

Up to 500 lb capacity with single or multiple shakers

Impulse hammers available

Boundary Condition Capability Fixed-Base, Free-Free

Large seismic mass bases up to 20,000 lbs.

General Vibration Laboratory

The GVL has five primary testbeds; however,

unique testbeds can be constructed as

necessary to meet a specific test project.

Inside the GVL enclosure (removable ceiling

panels), the 40,000 lbf shakers for the vertical

and horizontal testbeds are mounted to seismic

floors. Outside the GVL enclosure are two more

testbeds, an 18,000 lbf vertical testbed and

a 20,000 lbf horizontal testbed. The GVL also

houses a 8,000 lbf human-rated vibration

testbed. The laboratory typically provides

testing for subsystems and smaller

components from as large as an aircraft rudder

to as small as a 4 oz heart rate monitor.

Spacecraft Vibration Laboratory

The SVL was specifically designed for

vibration testing of large structures and

used for Apollo, Skylab, Space Shuttle,

and Space Station tests. It provides a

vast array of access platforms to the

test articles. Massive test articles can

be supported by pneumatic springs

and subjected to high-force inputs,

which simulate rocket-induced

discrete-frequency or random loads

with distributed mechanical shakers.

Typical testing functions performed

include high-force vibration (random

and sine), shock vibration, and fixed-

base and free-free modal testing.

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